Fungicidal mixtures

ABSTRACT

The invention relates to fungicidal compositions comprising an acceptable carrier and/or surface active agent and synergistically effective amounts of  
     (a) at least one azolopyrimidine of formula I  
                 
 
     in which R 1  through R 2 , L, A and n have the meaning given in claim  1;    
     (b) and at least one melanin biosynthesis inhibitor (MBI), preferably a phenoxyamide of formula II  
                 
 
     wherein R 5  through R 9 , Y and m have the meaning given in claim  2;  and to a method of controlling the growth of phythopathogenic fungi at a locus which comprises applying synergistically effective amounts of at least one azolopyrimidine of formula I (a) and at least one MBI (b) to the locus.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a fungicidal compositioncomprising a fungicidally acceptable carrier and/or surface active agentand synergistically effective amounts of

[0002] (a) at least one azolopyrimidine of formula I

[0003] in which

[0004] R¹ and R² each independently represent hydrogen or an optionallysubstituted alkyl, alkenyl, alkynyl, alkadienyl, aryl, heteroaryl,cycloalkyl, bicycloalkyl or heterocyclyl group, or

[0005] R¹ and R² together with the adjacent nitrogen atom represent anoptionally substituted heterocyclic ring,

[0006] R³ represents a hydrogen or a halogen atom or an alkyl group,

[0007] R⁴ represents hydrogen or an alkyl or aryl group,

[0008] L represents a halogen atom or an optionally substituted alkyl oralkoxy group,

[0009] A represents N or CR⁵, wherein R⁵ has the meaning given for R⁴,and

[0010] n is 0 or an integer between 1 and 5; and

[0011] (b) and at least one fungicidal active ingredient which iscapable of inhibiting the melanin biosynthesis in particular inPyricularia oryzae the causal agent of the rice blast disease.

[0012] The fungicidal compounds of formula I are known from U.S. Pat.Nos. 4,567,263 and 5,593,996.

[0013] The class of melanin biosynthesis inhibitors (MBI) are chemicalcompounds which are capable of diminishing the in-vivo synthesis ofmelanin by inhibiting any of the reductase and/or dehydratase enzymeswhich are responsible for converting tetrahydroxynaphthalene intodihydroxynaphthalene. This class of compounds includes the followingknown compounds: carpropamid, chlobenthiazione, diclocymet, pyroquilon,phthalide, tricyclazole and certain phenoxyamides, which are known forexample from EP 0 262 393 and Japanese patent application JP 5-9165-A.

[0014] However, there is no hint to combine the compounds of formula I,with a MBI. Moreover, there is no hint that such mixtures can beadvantageously be used for controlling rice diseases such as rice blastand rice sheath blight and others.

[0015] Surprisingly, a strong synergy between the compounds of formula Iand MBIs in field trials was found when these two compounds were in-tankmixed and when the activity of these co-formulations was compared withthat of the solo formulations of each active ingredient.

[0016] A mixture of fungicides shows synergistic effect if thefungicidal activity of the mixture is larger than the sum of activitiesof the separately applied compounds. The expected fungicidal activityfor a given mixture of two fungicides can also be calculated as follows(See Colby, S. R., “Calculating synergistic and antagonistic response ofherbicide combinations”, Weeds 15, pp 20-22 (1967):

EE=x+y−x·y/100

[0017] wherein

[0018] x is the efficacy in % compared with an untreated control upontreatment with a fungicidal active ingredient A at a dose rate a;

[0019] y is the efficacy in % compared with an untreated control upontreatment with a fungicidal active ingredient B at a dose rate b;

[0020] EE is the expected efficacy with a combination of fungicidalactive ingredients A and B at a dose of a+b, respectively.

[0021] If the actual efficacy (E) exceeds the expected (calculated) one(EE), the mixture displays a synergistic effect.

SUMMARY OF THE INVENTION

[0022] The present invention includes a fungicidal compositioncomprising an acceptable carrier and/or surface active agent andsynergistically effective amounts of at least one compound of formula I,and at least one melanin biosynthesis inhibitor (MBI).

[0023] The present invention also includes a method of controlling thegrowth of phytopathogenic fungi at a locus which comprises applyingsynergistically effective amounts of at least one azolopyrimidine offormula I and at least one MBI to the locus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Preferred compounds of formula I include those wherein

[0025] R¹ and R² together with the interjacent nitrogen atom representan optionally substituted 6-membered heterocyclic ring, in particular a4-methylpiperidine ring, or wherein

[0026] R¹ represents a C₁₋₆ alkyl, in particular an isopropyl group, aC₁₋₆ haloalkyl, in particular a 2,2,2-trifluoroethyl or a1,1,1-trifluoroprop-2-yl group, or a C₃₋₈ cycloalkyl group, inparticular a cyclopentyl or cyclohexyl group and R² represents ahydrogen atom or a C₁₋₆ alkyl group and/or wherein

[0027] wherein L¹ represents a halogen atom, preferably fluorine orchlorine and L² and L³ each independently represent a hydrogen atom or ahalogen atom, preferably fluorine, in particular wherein L¹ representsfluorine, L² represents hydrogen and L³ represents chlorine or whereinL¹ through L³ represent fluorine, and/or wherein

[0028] Hal represents a chlorine atom.

[0029] In a particularly preferred embodiment the azolopyrimidine is thecompound of formula IA

[0030] wherein L and n have the meaning given for formula I, and

[0031] R¹ represents an alkyl or haloalkyl group,

[0032] R² represents a hydrogen atom, or

[0033] R¹ and R² together represents an optionally substituted alkylenegroup having 3 to 6 carbon atoms in the main chain, in which one CH₂group may be replaced by O or NH, and

[0034] Hal denotes a halogen atom.

[0035] Particularly preferred are the following azolopyrimidines:

[0036]5-chloro-6-(2-chloro-6-fluorophenyl)-7-(4-methylpiperid-1-yl)-[1,2,4]triazolo[1,5-a]pyrimidinecoded Azoloyrimidine A,

[0037]5-chloro-6-(2-chloro-6-fluorophenyl)-7-isopropylamino-[1,2,4]triazolo[1,5-a]pyrimidinecoded Azoloyrimidine B,

[0038]5-chloro-6-(2-chloro-6-fluorophenyl)-7-(2,2,2-trifluoroethylamino)-[1,2,4]triazolo[1,5-a]pyrimidinecoded Azoloyrimidine C and

[0039]5-chloro-6-(2,4,6-trifluorophenyl)-7-(1,1,1-trifluoroprop-2-ylamino)-[1,2,4]triazolo[1,5-a]pyrimidinecoded Azoloyrimidine D.

[0040] Preferred MBIs include carpropamid, chlobenthiazione,dicyclocymet, pyroquilon, phthalide and tricyclazole.

[0041] Furthermore, the phenoxyamides of formula II are preferred MBIs:

[0042] wherein

[0043] R⁵ and R⁶ each independently represent a hydrogen atom or anoptionally substituted alkyl group;

[0044] R⁷ independently represents a hydrogen atom or an optionallysubstituted alkyl group

[0045] R⁸ and R⁹ each independently represent a hydrogen atom or anoptionally substituted alkyl or alkenyl group; or R⁸ and R⁹together mayrepresent an alkylene group;

[0046] Y each independently represents a halogen atom or an optionallysubstituted alkyl or alkenyl group or a cyano or nitro group;

[0047] m is 0 or an integer of 1, 2, 3 or 4.

[0048] Particularly preferred phenoxyamides are the compounds of formulaIIA

[0049] wherein R⁹, Y and m have the meaning given, in particular wherein

[0050] in which Y′ represents a hydrogen atom or a methyl group and/orwherein R⁹ represents a C₁₋₈-alkyl group.

[0051] Most preferred areN-(1-cyano-1,2-dimethyl-propyl)-2-(2,4-dichlorophenoxy)-propionamide, inparticular a mixture of (2R)- and(2R/S)-N-(1-cyano-1,2-dimethyl-propyl)-2-(2,4-dichlorophenoxy)-propionamidecoded Propionamide E andN-(1-cyano-1-ethyl-propyl)-2-(2,4-dichloro-3-methylphenoxy)-propionamidecoded Propionamide F.

[0052] Preferred formulations of this invention include those comprisingthe following constituents:

[0053] a carrier agent;

[0054] at least one azolopyrimidine of formula I,

[0055] at least one MBI, in particular a phenoxyamide of formula II,

[0056] optionally a foam breaking agent, in particular a mixture ofperfluoroalkyphosphonic acids and/or perfluoroalkylphosphinic acids, inparticular Defoamer SF or Fluoweft PL, which are commercially availablefrom Clariant GmbH.

[0057] The compound of formula I and the MBI are to be applied together,in synergistically effective amounts. These synergistic mixtures exhibitan extraordinary efficacy against a broad range of phytopathogenicfungi, in particular against fungi from the classes ascomycetes,basidiomycetes and deuteromycetes. Therefore, they can be appliedadvantageously against rice diseases. They are systemic and may beapplied as leaf, into water, seed dressing, nursery box or soilfungicides.

[0058] The mixture according to the invention may be preferably appliedfor controlling phytopathogenic fungi of the genera: Pyricularia,Rhizoctonia, Cochliobolus, Cercospora, Magnaporthe, Altemaria,Drechslera, Fusarium, Gerlachia, Achlya, Sclerotium, Gibberella,Mycosphaerella, Balansia, Sarocladium, Pythium, Phoma, Phytophthora,Bipolaris, Curvularia, Sarocladium, Nigrospora, Entyloma, Sclerophthora,Cylindrocladium, Gaeumannomyces, Myrothecium, Mucor, Rhizopus, Tilletia,Ustilago, Ustilaginoidea, Bipolaris, Sclerotium, Botrytis, Venturia,Erysiphe, Septoria, Puccinia, Leptosphaeria and Pseudocercosporella, inparticular the species Rhizoctonia solani, Cochliobolus miyabeanus,Spharulina oryzina, Leptosphaeria slavini and Pyricularia otyzae.

[0059] The application rate of the compound of formula I according tothis invention is usually in the range of 5 to 2000 grams of activeingredient (g a.i.) per hectare, with rates between 30-500 g a.i./haoften achieving satisfactory control. The optimal rate for a specificapplication will depend on the crop(s) under cultivation and thepredominant species of infesting fungus, and readily may be determinedby established biological tests known to those skilled in the art.

[0060] In general, the preferred application rate of the compounds offormula I is in the range of 10 to 500 g a.i./ha, more preferably 30-300g a.i./ha.

[0061] The optimal rate for the MBI will depend on the crop(s) undercultivation and the level of infestation by the fungus, and can readilybe determined by established biological tests.

[0062] The ratio (by weight) of the compound of formula I to the MBI isas a rule, from 1:100 to 100:1. The preferred ratio formula I: MBI mayvary, e.g., from about 1:50 to about 50:1, in particular from about 1:4to about 4:1.

[0063] The active compounds will be formulated together in a suitableratio according to the present invention, together with usual carriersand/or additives known in the art.

[0064] Accordingly the invention further provides a fungicidalcomposition which comprises a carrier and, as active ingredient, atleast one compound of formula I as defined above and at least one MBI.

[0065] A method of making such a composition is also provided whichcomprises bringing the compound of formula I and the MBI as definedabove into association with at least one carrier. It is also envisagedthat different isomers or mixtures of isomers of the compound of formulaI and/or the MBI may have different levels or spectra of activity andthus compositions may comprise individual isomers or mixtures ofisomers.

[0066] A composition according to the invention preferably contains from0.1% to 99.9%, preferably 0.2 to 80% by weight (w/w) of activeingredients.

[0067] A carrier in a composition according to the invention is anymaterial with which the active ingredient is formulated to facilitateapplication to the locus to be treated. which may for example be aplant, seed. foliage. soil. or into the water where the plant grows, orto the roots, or to facilitate storage, transport or handling. A carriermay be a solid or a liquid, including material which is normally a gasbut which has been compressed to form a liquid.

[0068] The compositions may be manufactured into, e.g., emulsion oremulsifiable concentrates, solutions, oil in water emulsions, wettablepowders, soluble powders, suspension concentrates, solutions, dusts,granules, water dispersible granules, tablets, aerosols, micro-capsules,gels and other formulation types by well-established procedures. Theseprocedures include intensive mixing and/or milling of the activeingredients with other substances, such as fillers, solvents, solidcarriers, surface active compounds (surfactants), and optionally solidand/or liquid auxilaries and/or adjuvants. The form of application suchas spraying, atomizing, dispersing or pouring may be chosen like thecompositions according to the desired objectives and the givencircumstances.

[0069] Solvents may be aromatic hydrocarbons, e.g. Solvesso® 200,substituted naphthalenes, phthalic acid esters, such as dibutyl ordioctyl phthalate, aliphatic hydrocarbons, e.g. cyclohexane orparaffins, alcohols and glycols as well as their ethers and esters, e.g.ethanol, ethyleneglycol mono- and dimethyl ether, ketones such ascyclohexanone, strongly polar solvents such as N-methyl-2-pyrrolidone,or γ-butyrolactone, higher alkyl pyrrolidones, e.g. n-octylpyrrolidoneor cyclohexylpyrrolidone, epoxidized plant oil esters, e.g. methylatedcoconut or soybean oil ester and water. Mixtures of different liquidsare often suitable.

[0070] Solid carriers, which may be used for dusts, wettable powders,water dispersible granules, or granules, may be mineral fillers, such ascalcite, talc, kaolin, montmorillonite or attapulgite or others. Thephysical properties may be improved by addition of highly dispersedsilica gel or polymers. Carriers for granules may be porous material,e.g. pumice, kaolin, sepiolite, bentonite; non-sorptive carriers may becalcite or sand or others. Additionally, a multitude of pre-granulatedinorganic or organic materials may be used, such as dolomite or crushedplant residues.

[0071] Pesticidal compositions are often formulated and transported in aconcentrated form which is subsequently diluted by the user beforeapplication. The presence of small amounts of a carrier which is asurfactant facilitates this process of dilution. Thus, preferably atleast one carrier in a composition according to the invention is asurfactant. For example, the composition may contain at two or morecarriers, at least one of which is a surfactant.

[0072] Surfactants may be nonionic, anionic, cationic or zwitterionicsubstances with good dispersing, emulsifying and wetting propertiesdepending on the nature of the compound according to general formula Ito be formulated. Surfactants may also mean mixtures of individualsurfactants.

[0073] Wettable powders of this invention suitably will contain 5 to 90%w/w of active ingredient and, in addition to a solid inert carrier, 3 to10% w/w of dispersing and wetting agents and, where necessary, 0 to 10%w/w of stabilizer(s) and/or other additives such as penetrants orstickers. Dusts may be formulated as a dust concentrate having a similarcomposition to that of a wettable powder but without a dispersant, andmay be diluted in the field with further solid carrier to give acomposition usually containing 0.5 to 10% w/w of active ingredient.Water dispersible granules and granules may have a size between 0.15 mmand 2.0 mm and may be manufactured by a variety of techniques.Generally, these granules will contain 0.5 to 90% w/w active ingredientand 0 to 20% w/w of additives such as stabilizer, surfactants, slowrelease modifiers and binding agents. Emulsifiable concentrates maycontain, in addition to a solvent or a mixture of solvents, 1 to 80% w/vactive ingredient, 2 to 20% w/v emulsifiers and 0 to 20% w/v of otheradditives such as stabilizers, penetrants and corrosion inhibitors.Suspension concentrates are suitably milled so as to obtain a stable,non-sedimenting, flowable product and typically contain 5 to 75% w/vactive ingredient, 0.5 to 15% w/v of dispersing agents, 0.1 to 10% w/vof suspending agents such as protective colloids and thixotropic agents,0 to 10% w/v of other additives such as defoamers, corrosion inhibitors,stabilizers, penetrants and stickers, and water or an organic liquid inwhich the active ingredient is substantially insoluble; certain organicsolids or inorganic salts may be dissolved in the formulation to assistin preventing sedimentation and crystalization or as antifreeze agents.

[0074] Aqueous dispersions and emulsions, for example compositionsobtained by diluting the formulated product according to the inventionwith water, also lie within the scope of the invention.

[0075] Of particular interest in enhancing the duration of theprotective activity of the compounds of this invention is the use of acarrier which will provide slow release of the pesticidal compounds intothe environment of a plant which is to be protected.

[0076] The biological activity of the active ingredient can also beincreased by including an adjuvant in the spray dilution. An adjuvant isdefined here as a substance which can increase the biological activityof an active ingredient but is not itself significantly biologicallyactive. The adjuvant can either be included in the formulation as acoformulant or carrier, or can be added to the spray tank together withthe formulation containing the active ingredient.

[0077] As a commodity, the compositions may preferably be in aconcentrated form whereas the end user generally employs dilutedcompositions. The compositions may be diluted to a concentration down to0.001% of active ingredient. The doses usually are in the range from0.01 to 10 kg a.i./ha.

[0078] Examples of formulations which can be used according to theinvention are: SC-A active ingredient Azolopyrimidine A 100.0 gDispersing agent Morwet D425¹⁾ 25.0 g Dispersing agent Pluronic ®PE10500²⁾ 5.0 g Antifoaming agent Rhodorsil ® 426R³⁾ 1.5 g Dispersingagent Rhodopol ® 23³⁾ 2.0 g Antifreezing agent Propylene glycol 80.0 gBiocidal agent Proxel ® GXL⁴⁾ 1.0 g Water to 1000 ml SC-B/SC-D activeingredient Azolopyrimidine B or D 100.0 g Dispersing agent Soprophor ®FL³⁾ 30.0 g Antifoaming agent Rhodorsil ® 426R³⁾ 1.5 g Dispersing agentRhodopol ® 23³⁾ 2.0 g Antifreezing agent Propylene glycol 80.0 gBiocidal agent Proxe ®l GXL⁴⁾ 1.0 g Water to 1000 ml SC-E activeingredient Propionamide E 200.0 g Dispersing agent Soprophor ® FL³⁾ 25.0g Antifoaming agent Rhodorsil ® 426R³⁾ 1.5 g Dispersing agent Rhodopol ®23³⁾ 2.0 g Antifreezing agent Propylene glycol 80.0 g Biocidal agentProxel ® GXL⁴⁾ 1.0 g Water to 1000 ml SC-A/E active ingredientAzolopyrimidine A 60.0 g active ingredient Propionamide E 120.0 gDispersing agent Soprophor ® FL³⁾ 25.0 g Antifoaming agent Rhodorsil ®426R³⁾ 1.5 g Dispersing agent Rhodopol ® 23³⁾ 2.0 g Antifreezing agentPropylene glycol 80.0 g Biocidal agent Proxel ® GXL⁴⁾ 1.0 g Water to1000 ml DC-A active ingredient Azolopyrimidine A 100.0 g Wetting agentPluronic ® PE6400²⁾ 50.0 g Dispersing agent Lutensol ® TO 12²⁾ 50.0 gSolvent benzyl alcohol to 1000 ml DC-B active ingredient AzolopyrimidineB 100.0 g Wetting agent Pluronic ® PE6400²⁾ 50.0 g Dispersing agentLutensol ® TO 12²⁾ 50.0 g Solvent benzyl alcohol to 1000 ml

[0079] The formulation SC-E comprising Propionamide E is in-tank mixedwith any of the other formulations SC-A, SC-B, SC-D, DC-A or DC-B whichcomprise the Azolopyrimidines A, B or D.

[0080] In a preferred embodiment the active ingredients are added to thetank mix together, each as a solo formulation.

[0081] Therefore, the present invention relates to a kit for thepreparation of a spray mixture consisting of two separate formulations:

[0082] (i) a formulation which comprises at least one azolopyrimidine offormula I, in particular Azolopyrimidines A, B, C or D, conventionaladjuvants and carriers;

[0083] (ii) a formulation which comprises at least one MBI, preferably aphenoxyamide of formula II, in particular Propionamide E or F,conventional adjuvants and carriers.

[0084] In a preferred embodiment the kit includes two bottles withdispensing means which allow easy and correct addition of theformulations (i) and (ii) to the tank mix.

[0085] The formulation SC-A/E comprising Azolopyrimidine A andPropionamide E can be used directly for preparing the tank mix accordingto the present invention.

[0086] A composition according to the invention preferably contains from0.5% to 95% by weight of active ingredients.

[0087] The compositions of this invention may be diluted down to aconcentration of 0.0001% of active ingredients.

[0088] The compositions of this invention can be applied to the plantsor their environment simultaneous with or in succession with otheractive substances. These other active substances can be eitherfertilizers, agents which donate trace elements or other preparationswhich influence plant growth. However, they can also be selectiveherbicides, insecticides, fungicides, bactericides, nematicides,algicides, molluscicides, rodenticides, virucides, compounds inducingresistance into plants, biological control agents such as viruses,bacteria, nematodes, fungi and other microorganisms, repellents of birdsand animals, and plant growth regulators, or mixtures of several ofthese preparations, if appropriate together with other carriersubstances conventionally used in the art of formulation, surfactants orother additives which promote application.

[0089] Examples of the other fungicidal compounds are anilazine,azoxystrobin, benalaxyl, benomyl, binapacryl, bitertanol, blasticidin S,Bordeaux mixture, bromuconazole, bupirimate, captafol, captan,carbendazim, carboxin, chlorothalonil, chlozolinate, copper-containingcompounds such as copper oxychloride, and copper sulfate, cycloheximide,cymoxanil, cypofuram, cyproconazole, cyprodinil, dichlofluanid,dichlone, dichloran, diclobutrazol, diclomezine diethofencarb,difenoconazole, diflumetorim, dimethirimol, dimethomorph, diniconazole,dinocap, ditalimfos, dithianon, dodemorph, dodine, edifenphos,epoxiconazole, etaconazole. ethirimol, etridiazole, famoxadone,fenapanil, fenarimoi, fenbuconazole, fenfuram, fenhexamid, fenpiclonil,fenpropidin, fenpropimorph, fentin, fentin acetate, fentin hydroxide,ferimzone, fluazinam, fludioxonil, flumetover, fluquinconazole,flusilazole, flusulfamide, flutolanil, flutriafol, folpet,fosetyl-aluminium, fuberidazole, furalaxyl, furametpyr, guazatine,hexaconazole, imazalil, iminoctadine, ipconazole, iprodione,iprovalicarb, isoprothiolane, kasugamycin, kitazin P, kresoxim-methyl,mancozeb, maneb, mepanipyrim, mepronil, metalaxyl, metconazole,methfuroxam, myclobutanil, neoasozin, nickel dimethyidithiocarbamate,nitrothalisopropyl, nuarimol, ofurace, organo mercury compounds,oxadixyl, oxycarboxin, penconazole, pencycuron, phenazineoxide, polyoxinD, polyram, probenazole, prochloraz, procymidione, propamocarb,propiconazole, propineb, pyrazophos, pyrifenox, pyrimethanil, pyroxyfur,quinomethionate, quinoxyfen, quintozene, spiroxamine, SSF-126, SSF-129,streptomycin sulfur, tebuconazole, tecloftalame, tecnazene,tetraconazole, thiabendazole, thifluzamide, thiophanate-methyl, thiram,tolclofosmethyl, tolylfluanid, triadimefon, triadimenol, triazbutil,triazoxide, tridemorph, triflumizole, triforine, triticonazole,validamycin A, vinclozolin, XRD-563, zarilamid, zineb, ziram.

[0090] Examples of insecticidal compounds are alpha-cypermethrin,benfuracarb, BPMC, buprofezine, carbosulfan, cartap, chlorfenvinphos,chlorpyrifos-methyl, cycloprothrin, cypermethrin, esfenvalerate,ethofenprox, fenpropathrin, flucythrinate, flufenoxuron, hydramethylnon,imidacloprid, isoxathion, MEP, MPP, nitenpyram, PAP, permethrin,propaphos, pymetrozine, silafluofen, tebufenozide, teflubenzuron,temephos, terbufos, tetrachlorvinphos and triazamate.

[0091] Examples of biological control agents are: Bacillusthuringiensis, Verticillium lecanii, Autographica californica NPV,Beauvaria bassiana, Ampelomyces quisqualis, Bacilis subtilis,Pseudomonas fluorescens, Steptomyces griseoviridis and Trichodermaharzianum.

[0092] Examples of chemical agents that induce systemic acquiredresistance in plants such are: isonicotinic acid or derivatives thereof,2,2-dichloro-3,3-dimethylcyclopropylcarboxylic acid and BION.

[0093] The present invention is of wide applicability in the protectionof crop and ornamental plants against fungal attack. Preferred crop isrice and in particular paddy-rice. The duration of the protection isnormally dependent on the individual compound selected, and also avariety of external factors, such as climate, whose impact is normallymitigated by the use of a suitable formulation.

[0094] The following examples further illustrate the present invention.It should be understood, however, that the invention is not limitedsolely to the particular examples given below.

EXAMPLES

[0095] For the field study formulated Azolopyrimidine A, B or D (100 g/lDC-A or DC-B; 100 g/l SC-D) and formulated Propionamide E (200 g/l SC-E)were used.

[0096] The field tests of the method of the present invention wereconducted on rice fields in the Philipines, in Brazil and Japan.

[0097] Materials and Application Method:

[0098] Rice seed of variety ‘IR-50’ was sown in a sand/garden soil in0.07 sq.m. (0.23×0.3 m) plastic boxes. Fourteen days later, in theZ14/20 growth stage, the plants were sprayed with the fungicidalcompounds for the first time. The formulated compounds were weighed outand diluted with water. Equivalents of 100, 200 and 400 g activeingredients per ha were applied with a hand hold atomizer using 1000 lspray volume per ha. The doses of the single compounds and of themixtures are given in the tables of results below. There were threereplicated boxes per treatment. The spraying was repeated 7 days afterthe first application using the same compounds/compound mixtures at thesame dose rates and spray volume/ha.

[0099] Evaluation of the Disease:

[0100] Assessments of the rice blast disease and the rice sheath blightdisease took place 14 days after the first application (=7 days afterthe second application) of the compounds. Percent leaf area infected wasevaluated. The efficacy of the compounds/compounds mixtures to controlthe diseases was calculated by using the formula:${\% \quad {disease}\quad {control}} = {100 - {\frac{\% \quad {disease}\quad {in}\quad {treated}\quad {plants}}{\% \quad {disease}\quad {in}\quad {untreated}\quad {plants}} \times 100\%}}$

[0101] Determination of synergy:

[0102] Synergy was calculated using the % disease control values ofspecific treatments for the two COLBY formula given hereinabove

Example 1 Control of Rice Blast Caused by Pyricularia oryzae

[0103] Infection with Pyricularia oryzae:

[0104] Three hours after the first compound application (when the plantswere dry) an in-vitro grown conidial suspension of Pyricularia oryzaewas inoculated onto the foliar surfaces of the rice plants using a handheld atomizer. The conidial concentration was about 1 million per ml.Plants were then placed into a moist chamber for 24 h at 24-26 degree Cwith about 100% relative humidity. The plants were then moved outdoorsuntil the rice blast disease could be evaluated.

[0105] The formulations applied, the dosage rates of the activeingredients applied (expressed in grams of active ingredient perhectare), the results expressed as efficacy of disease control and theexpected efficacies calculated according to Colby's formula are setforth below in table I. TABLE I Percent rice blast control of DC-A andDC-B and SC-E when applied alone or in mixture as found in theexperiment and as expected using COLBY's formula efficacy (%)Formulation dose (g/ha) obtained expected DC-A 200 24 — DC-A 400 65 —DC-B 200 28 — DC-B 400 61 — SC-E 100 18 — SC-E 200 41 — DC-A + SC-E200 + 100 84 38 DC-A + SC-E 400 + 100 87 72 DC-B + SC-E 200 + 100 73 41DC-B + SC-E 400 + 100 76 68

Example 2 Control of Rhizoctonia solani

[0106] Infection with Rhizoctonia solani:

[0107] Three hours after the second application of thecompounds/compounds mixtures, the plants were inoculated withRhizoctonia solani (gown in rice grain-hull medium) by evenly sprinklingthe inoculum on the soil surface at the basis of the plants. Plants werethen placed into a moist chamber for 24 h. After that the plants weremoved outdoors until the rice sheath blight disease could be evaluated.

[0108] The formulation applied, the dose rates of the active ingredientsapplied (expressed in grams of active ingredient per hectare), theresults expressed as efficacy of disease control and the expectedefficacies calculated according to Colby's formula are set forth belowin table II.

[0109] Disease symptoms (rice blast and rice sheath blight) wereassessed 7 days days after the second application (DAT) of the products.TABLE II Percent rice sheath blight control of DC-A and DC-B and SC- Ewhen applied alone or in mixture as found in the experiment and asexpected using COLBY's formula: efficacy (%) rice sheath blightFormulation dose (g/ha) obtained expected DC-A 200 45 — DC-A 400 87 —DC-B 200 75 — DC-B 400 85 — SC-E 100 18 — SC-E 200 23 — DC-A + SC-E200 + 100 88 55 DC-A + SC-E 400 + 100 89 89 DC-B + SC-E 200 + 100 98 79DC-B + SC-E 400 + 100 95 88

Example 3 Control of Pyricularia oryzae

[0110] For another experiment, established in the field in Japanpaddy-rice plants of the variety “Koshihikari” were grown up in nurseryboxes, and were transplanted to the field in plots of 10 sqm. 46 and 53days after transplanting, the plants were sprayed with the formulationsSC-A and SC-E and a in-tank mixture of these formulations after dilutionin water and applying the equivalent of 1 liter per plot with a sprayingequipment. The compound A was formulated as a 100 g/l SC.

[0111] Each treatment was applied in three plots (3 replicates). Therewere also untreated plots. 15 days after the second treatment 17% of theleaf area of the untreated rice plants (controls) were infected with therice blast disease. The disease level (% infected leaf area) was alsoassessed in the treated plants, and the efficacy (in %) of the treatmentwas measured. The effects of mixtures according to the invention and thesolo compounds are given in Table III. TABLE III Percent rice blastcontrol of SC-A and SC-E when applied alone or in mixture as found inthe experiment and as expected using COLBY's formula: efficacy (%) ricesheath blight Formulation dose (g/ha) obtained expected SC-A  50 41 —SC-A 100 71 — SC-A 200 72 — SC-E 100 83 — SC-E 150 91 — SC-E 200 93 —SC-A + SC-E  50 + 100 96 90 SC-A + SC-E 100 + 100 97 95 SC-A + SC-E 50 + 150 95 95

Example 4 Control of Pyricularia oryzae

[0112] Rice variety IAC-165 was direct seeded in field plots in Brazil.Individual field plots were 9 m² and each treatment was replicated 3times. Overhead irrigation was used to ensure uniform germination anddisease development but an artificial inoculation was not necessary assufficient disease established itself naturally.

[0113] Two applications of each treatment were made, 7 days apart and ina water volume of 1000 l/ha. A visual assessment of disease control wasmade 14 days after the first application.

[0114] The effects of mixtures according to the invention (SC-D+SC-E)and the solo compounds are given in Table IV. TABLE IV Percent riceblast control of SC-D and SC-C when applied alone or in mixture as foundin the experiment and as expected using COLBY's formula efficacy (%)Formulation dose (g/ha) obtained expected SC-D  30 8 — SC-E 100 4 —SC-D + SC-E  30 + 100 29 12

[0115] Results:

[0116] The results given in tables I to IV show that mixtures of MBIs,such as phenoxyamides, and azolopyrimidines exhibit synergism.

What is claimed is:
 1. A fungicidal composition comprising an acceptablecarrier and/or surface active agent and synergistically effectiveamounts of (a) at least one azolopyrimidine of formula I

 in which R¹ and R² each independently represent hydrogen or anoptionally substituted alkyl, alkenyl, alkynyl, alkadienyl, aryl,heteroaryl, cycloalkyl, bicycloalkyl or heterocyclyl group, or R¹ and R²together with the adjacent nitrogen atom represent an optionallysubstituted heterocyclic ring, R³ represents a hydrogen or a halogenatom or an alkyl group, R⁴ represents hydrogen or an alkyl or arylgroup, L represents a halogen atom or an optionally substituted alkyl oralkoxy group, A represents N or CR⁵, wherein R⁵ has the meaning givenfor R⁴, and n is 0 or an integer between 1 and 5; and (b) at least onefungicidal active ingredient which is capable of inhibiting thebiosynthesis of melanin.
 2. A compositions as claimed in claim 1,wherein the melanin biosynthesis inhibitor is a phenoxyamide of formulaII

wherein R⁵ and R⁶ each independently represent a hydrogen atom or anoptionally substituted alkyl group; R⁷ independently represents ahydrogen atom or an optionally substituted alkyl group R⁸ and R⁹ eachindependently represent a hydrogen atom or an optionally substitutedalkyl or alkenyl group; or R⁸ and R⁹together may represent an alkylenegroup; Y each independently represents a halogen atom or an optionallysubstituted alkyl or alkenyl group or a cyano or nitro group; m is 0 oran integer of 1, 2, 3 or
 4. 3. A compositions as claimed in claim 1,wherein the azolopyrimidine is a compound of formula IA,

wherein L and n have the meaning given for formula I, and R¹ representsan alkyl or haloalkyl group, R² represents a hydrogen atom, or R¹ and R²together represents an optionally substituted alkylene group having 3 to6 carbon atoms in the main chain, in which one CH₂ group may be replacedby O or NH, and Hal denotes a halogen atom.
 4. A composition as claimedin claim 3 containing a compound of formula IA, wherein Hal denotes achlorine atom, and


5. A composition as claimed in claim 4, wherein the azolopyrimidine isselected from the group consisting of:5-chloro-6-(2-chloro-6-fluorophenyl)-7-(4-methylpiperid-1-yl)-[1,2,4]triazolo[1,5-a]pyrimidine,5-chloro-6-(2-chloro-6-fluorophenyl)-7-isopropylamino-[1,2,4]triazolo[1,5-a]pyrimidine,5-chloro-6-(2-chloro-6-fluorophenyl)-7-(2,2,2-trifluoroethylamino)-[1,2,4]triazolo[1,5-a]pyrimidine,and 5-chloro-6-(2,4,6-trifluorophenyl)-7-(1,1,1trifluoroprop-2-ylamino)-[1,2,4]triazolo[1,5-a]pyrimidine.
 6. Acomposition as claimed in claim 2, wherein the phenoxyamide is acompound of formula IIA

wherein R⁹, Y and m have the meaning given.
 7. A composition as claimedin claim 6 containing a compound of formula IIA, wherein

in which Y′ represents a hydrogen atom or a methyl group.
 8. Acomposition as claimed in claim 7 containing a compound of formula IIA,wherein R⁹ represents a C₁₋₈-alkyl group.
 9. A composition as claimed inclaim 1, wherein the ratio (by weight) of the melanin biosynthesisinhibitor (b) to the azolopyrimidine of formula I (a) is from 0.1:1 to10:1.
 10. Method of controlling the growth of phytopathogenic fungi at alocus which comprises applying synergistically effective amounts of atleast one azolopyrimidine of formula I and at least one melaninbiosynthesis inhibitor as claimed in claim 1 to the locus.
 11. Method ofcontrolling rice diseases at a locus which comprises applyingsynergistically effective amounts of at least one azolopyrimidine offormula I and at least one melanin biosynthesis inhibitor as claimed inclaim 1 to the locus.